142 GENETICS IN RELATION TO AGRICULTURE 
color in corn. Taking into account the white dominant factor for 
aleurone coloration, the following genotypes may be obtained: 
WWecPP = white 
wwCCPP = purple 
wwecPP = white 
wwCCpp = white 
wwecpp = white 
WwcP WCp WceP Wep wCP wCp weP wep 
WCP|WWCCPP |WWCCPp| WWCcPP | WWCcPp | WwCCPP | WwCCPp | WwCcPP | WwCcPp 
White White White White White White White White 
0:1 0:1 0:1 0:1 1:3 3:13 3:13 9:55 
WCp| WWCCPp| WWCCpp| WWCcPp | WWCcpp | WwCCPp | WwCCpp | WwCcPp WwCcpp 
White White White White White White White White 
0:1 O:1 0:1 0:1 3:13 0:1 9:55 0:1 
WceP| WWCcPP | WWCcPp | WWecePP | WWeePp | WwCcPP | WwCcPp WwecPP WwecePp 
White White White White White White White White 
0:1 0:1 0:1 0:1 3:13 9:55 0:1 0:1 
Wep| WWCcPp | WWCcpp | WWecPp W Weepp WwCcPp WwCcpp WwecPp Wweepp 
White White White White White White White White 
0:1 0:1 0:1 0:1 9:55 0:1 0:1 0:1 
wCP| WwCCPP | WwCCPp | WwCcPP | WwCcPp | wwCCPP | wwCCPp wwCcPP wwCcPp 
White White White White Purple Purple Purple Purple 
1:3 3:13 3:13 9:55 1:0 3:1 3:1 (76 
wCp| WwCCPp | WwCCpp | WwCcPp 
White White White 
3:13 0:1 9:55 
WwCcpp | wwCCPp wwCCpp wwCcPp wwCcpp 
White Purple White Purple White 
0:1 3:1 0:1 O27. 0:1 
White White White White Purple Purple White White 
3:13 9:55 0:1 0:1 aise: 9:7 0:1 0:1 
weP WwCcPp WwCcpp WweePp 
White White White 
9:55 0:1 0:1 
Wweepp ,| wwCcPp wwCcpp wweePp wwecepp 
White Purple White White White 
0:1 SRY ( O:1 0:1 0:1 
| 
weP | WwCcPP | WwCcPp WwecPP | WweePp wwCcPP wwCcPp wweePP wwecP p 
Fia. 65.—F: checkerboard for cross of white (WWCCPP) X white (wwecpp) corn. 
In the Fs segregation ratio the purple is given first as in Fig. 64. 
The student will be able to figure out many different relations which 
exist. when such races are crossed. In this section only one will be con- 
sidered as an illustration of the working of such a system. If a white 
corn, WWCCPP, is crossed with a white corn, wwecpp, the F, is of the 
genetic constitution, WwCcPp, and is white on account of the action of 
W. The F2, however, shows some purple grains as will become apparent 
from a study of the accompanying checkerboard, Fig. 65. In F2 such a 
hybrid segregates in the ratio 55 white : 9 purple, and in F3 the families 
show the segregation ratios indicated in the proper squares of the checker- 
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